the main funda for clearing any exam in the world be it CA, CFA,CS etc "is to be at it"..
just keep on going fro ur aim , do not deviate, no matter how u prepare (ratta maaro or farre chalao, do anything),.just make sure u cover the whole syllabus at least once... just know ur syllabus inside out and there u have it.
no examiner on earth can fail u..
4 MONTHS IS SUFFICIENT BUT NO RELAXATION IS ALLOWED.............START WITH INDIRECT TAX AND COMPANY LAW FIRST.....IN LAW YOU CAN START WITH DIRECTORS CHAPTER AND IN INDIRECT TAX START WITH EXCISE.............